Surveyor&#39;s pin



April21,1970 BBGALLUP A 3,507,081 y sURvEYoR's 21N Filed Aug. '14. 1968 /NVENTR ,f6 g l A f6 53u05 GALLUP United States Patent Office Patented Apr. 21, 1970 3,507,081 SURVEYORS PIN Bruce B. Gallup, 1052 Chinquapin Lane, Virginia Beach, Va. 23451 Filed Aug. 14, 1968, Ser. No. 752,652 Int. Cl. E04h 13/00; F16b 19/00 U.S. Cl. 52-103 2 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The present invention relates, in general, to a surveyors pin for use in marking precise geographical points such as the boundary lines of property, and more particularly to a surveyors pin having an improved pin structure which is long lasting, easily locatable and inexpensive.

Surveyors markers of various types are, of course, well known, having been used for many years in the marking of geographic boundaries set out in the course of surveymg land, and in the placement or locations of cables, water mains and the like. Wooden stakes or lengths of metal pipes are most commonly used as markers because they are inexpensive and generally available. However, such markers are often unsatisfactory because of the fact that they deteriorate so quickly. The wooden markers tend to rot very quickly, and while the metal pipes last somewhat longer, they corrode in a relatively short period of time. Thus, wherever permanent markers are required for boundaries, it has been necessary to provide stone or concrete monuments. Such monuments are long lasting, and because of their size are generally easy to locate, but such monuments are very difficult and time consuming to install and thus'are not favored by surveyors. f

Because wooden stakes are easily broken off and because metal pipes are generally very diicultjto locate after having been in position for a period of time they are additionally unsatisfactory for use as long term or permanent markers. Further, the public in general is not able to determine whether such markers are being used for boundary marking, since they do not appear to have any special purpose, and thus they are often discarded unknowingly.

Some attempts have been made at providing an irnproved surveyors pin, but the results have not been satisfactory or commercially accepted either because they do not represent a substantial improvement over the presently available devices or because their expense is prohibitive.

Summary of the invention It is, therefore, an object of the present invention to provide a boundary marker which overcomes the disadvantages of prior boundary markers in that it is inexpensive, easy to locate, long lasting and simple to install.

It is a further object of the invention to provide a surveyors pin which may be easily located even after long periods of time either visually or by other means such as a radiation detector, which is easily identifiable as a boundary marker, and which identies the surveyor who used it.

The improved surveyors pin comprises a metal rod having a roughened outer surface which carries a brightly colored plastic sheath, or coating. The sheath extends substantially the full length of the pin, with the lower end of the metal rod exposed and sharpened for easy driving of the pin into the ground and with the upper end of the rod extending out of the sheath so that any flaring of the upper end during installation of the pin will not enlarge the outer diameter of the upper end of the pin. A plastic cap fits over the upper end of the pin and is adhesively bonded thereto. The surveyors name and certificate number may be stamped on the plastic cap to identify the surveyor who performed the work and to permit later surveyors of the same boundary to identify the person who originally laid out the boundary. Such identification would permit a quick reference to the names of property owners, sources of title and other pertinent information which would otherwise have to be obtained by time consuming and costly title searches in public records. In addition, such marking would clearly indicate to the public that the marker has a definite purpose and should not be disturbed.

The use of a brightly colored plastic material as a coating on the metal not only protects the metal but makes the pin highly visible. However, in areas where heavy undergrowth is likely to obscure boundary markers, or where the pins are likely to be driven under the surface of the ground, a modilication of the present invention would permit the use of a source of radioactivity within the pin. Such a source of radioactivity would have a half life of sufficiently long duration to permit reliable location of the marker over a relatively long period of time, yet would be of suiciently low activity as to present no safety hazard. With such an arrangement, the markers can be subsequently located through the use of a suitable radiation sensor.

Brief description of the drawings Further objects, features and advantages of the invention will be appreciated from a consideration of the following detailed description of preferred embodiments thereof, selected for purposes of illustration and shown in the accompanying drawings, in which:

FIG. l is a side view of a surveyors pin made in accordance with the present invention;

FIG. 2 is a sectional view of the pin of FIG. 1 taken along lines 2-2, showing the plastic sheath in cross section and the internal rod in full;

FIG. 3 is a top view of the cap used in conjunction with the pin of FIGS. 1 and 2; and

FIG. 4 is a cross sectional view of a modied version of the invention.

Description of the preferred embodiments Referring now to FIGS. 1 and 2, there is illustrated generally at 10 a surveyors pin made in accordance with the present invention. The pin consists of a central rod 12 which may be of steel, or other suitable material of similar strength, and an outer sheathing or covering 14 which preferably is of a strong, long-lasting plastic material. The plastic covering preferably is brightly colored for visibility, and is of a tough, weather resistant material which will provide a long life.

The metal core 12 extends below the plastic covering 14 at the lower end of the pin, as at 16, and this portion of the metal core preferably is sharpened to a point so that the pin may easily be driven into the ground. The metal rod, or core, 12 is barbed or knurled or otherwise roughened as at 18 to provide a suitable surface for receiving and holding the plastic sheath 14. This knurling prevents the plastic covering from sliding off of the core 12 when the pin is being driven into or removed from 3 the ground. Although the knurled portion is only shown on a portion of the core, it is to be understood that this is for purposes of illustration and that such roughening may extend the full length of the core. The plastic sheath may be applied to the central rod in any suitable manner; for example, by forcing an uncured plastic tube over the core, or by coating the core with a liquid plastic, and then curing the plastic.

The upper end of the metal rod 12 extends above the covering 14, as indicated at 20. This extension provides a surface for striking the pin when driving it into the ground, and permits any liaring of the metal core during the installation of the pin to occur above the plastic sheath. Since the core is of lesser diameter than the sheath, such flaring of the top of the core will not increase the outer diameter of the pin at its upper end, thus assuring that the cap member 22, rwhich is designed to cover the upper end of the pin, will still lit over the pin. Cap 22 is preferably made of the same plastic material as the sheath, and usually `will be of the same color. The cap tit snugly over the top of the pin, and is held in place there by means of a suitable adhesive material 24. The cap is slipped over the top of the pin after the pin has been driven in place, to seal the top of the pin and prevent corrosion of the metal core. The plastic cap may carry the name of the surveyor installing the pin, as indicated in FIG. 3, thus serving to identify the surveyor for the owner of the property marked by the pins. Such an identification would also aid the surveyor of adjoining property as well as a person resurveying the original property, for it would permit reference to the property data in the possession of the original surveyor.

The metal core used for the present device preferably is approximately We in diameter, with a standard length of 30". The sheathing may, for example, be Ms" thick, thereby producing a pin having an outer diameter of Sz. It will be apparent that pins of larger diameter and length may be made for use in areas such as swamps and forests -where visibility is a serious problem or where a long pin is required to reach solid ground, while shorter lengths may be made for use where underground obstacles such as cables or water mains are to be indicated.

Because of the simplicity of the pin thus far described, it can be mass produced at a cost which compares favorably with the cost of pins now commonly in use by surveyors. Without an appreciable increase in cost, then, a more permanent pin which may be easily located and which may be used to identify the surveyor doing the 4work is provided.

A modification of the basic pin illustrated in FIGS. 1 and 2 is shown in FIG. 4. In this embodiment, the metal core 12 is provided with a hollow bore 26 extending downwardly from the top of the metal rod a short distance. Bore 26 is adapted to receive a source of radioactive material 28. This source is adapted to produce radioactivity which may be detected by suitable sensor means, whereby the location of the pin may be determined even if it has been buried or otherwise hidden over a long period of years. The radioactive material may be held at the lower part of an elongated bore such as that illustrated in the figure, or may be placed in a shallow depression at the top of metal rod 12. If desired, a threaded rod may be inserted into the threaded bore 26 to hold the radioactive material in place, or other suitable covering means may be used, if desired. Preferably the radioactive material is inserted in the marker after the marker has been installed in the ground, so that the surveyor does not have to handle a radioactive pin. After the radioactive material is placed in the pin, cover 22 is placed over the pin and held in place by adhesive material 24, thus preventing renoval Vof the cap and exposure and removal of the radioactive material.

Thus, there has been described an improved surveyors pin which is inexpensive, more permanent than conventional surveyors pins yet simpler to install than the permannt concrete and stone markers often used in surveying. Further, the device is highly visible and easily identitiable as a boundary marker, thus reducing the likelihood that it will be dislodged accidentally by someone who does not recognize its purpose. In the modiiication utilizing radioactive material, the device may easily be located even if buried in the ground or in heavy undergrowth. Finally, the use of a separable cap on Iwhich the surveyors name or other identifying mark can be placed permits later surveyors to identify the original surveyor, thereby facilitating the job of obtaining data concerning the land being surveyed. Although specific embodiments of the invention have been illustrated and described in detail, it will be apparent that modifications may be made by persons skilled in the art without departing from the basic concept described herein. Therefore, it is desired that the invention not be limited to the speciiic embodiments described but that it include the various alternatives and modifications that fall within the true spirit and scope of the invention defined by the following claims.

I claim:

1. A durable, easily locatable surveyors boundary marking pin comprising:

(a) an elongated rod having a an upper blunt end, a

lower pointed end and an outside knurled surface;

(b) a brightly colored plastic sheath secured on'said rod and held in place by said knurled surface, one end of said sheath terminating inwardly of said lower pointed end, the other end of said sheath terminating contiguous to but inwardly of the blunt end of said rod, said sheath providing protection for said rod against corrosion and to provide a highly visible marker, said upper blunt end of said rod extending above said sheath whereby any flaring of the upper end of said rod when the pin is being installed will not cause the rod to exceed the outside diameter of the sheath; and

(c) a plastic cap having a diameter slightly larger than the outside diameter of the sheath and fitting snugly over the upper end of said pin and secured thereto, said cap being adapted to receive indicia, and

(d) locator means within said cap and sheath adjacent the blunt end of said pin.

2. The surveyors pin of claim 1, said locator means including a bore extending partially into said metal rod, and radioactive material Within said bore whereby said pin can be located by means of a radiation sensor.

References Cited UNITED STATES PATENTS 885,850 4/1908 Josenhans 52-104 1,802,924 4/1931 Myers 94--1.5 2,527,681 10/1950 Lewis 52--103 2,658,724 11/ 1953 Arps 175-41 3,066,447 12/1962 Reiterer 52f-155 3,106,960 10/1963 Doak 166-255 3,205,626 9/ 1965 Attenberger 52-103 3,256,655 6/1966 Teeter 52-155 3,378,967 4/1968 Baumeister 52-103 1,829,974 11/1931 Williams 85-10 2,724,303 11/ 1955 Holcomb 8,5--10 HENRY C. SUTHERLAND, Primary Examiner U.S. Cl. X.R. 

